Abstract: The invention relates to a surgical instrument, in particular a sliding shaft instrument, with a main part, and a moveable part relative thereto, with a handle attached to the main part, comprising a fixed grip and a grip actuating the moveable part, with at least one guide, through which, in relation to the main part, the moveable part is moveable between an initial position and a working position, and with a sliding surface attached to the movable part and pointing towards the main part, the sliding surface being slid along a guide surface attached to the main part and pointing towards the sliding surface, with at least the sliding surface or the guide surface are assigned to each other for the formation of a washable gap.